Intraocular device for dual incisions

ABSTRACT

A microsurgical device and methods of its use can be used for treatment of various conditions including eye diseases, such as glaucoma, using minimally invasive surgical techniques. A dual-blade device can be used for cutting the trabecular meshwork (“TM”) in the eye. The device tip provides entry into the Schlemm&#39;s canal via its size (i.e., for example, 0.2-0.3 mm width) and configuration where a ramp elevates the TM away from the outer wall of the Schlemm&#39;s canal and guides the TM to first and second lateral elements for creating first and second incisions through the TM. The dimensions and configuration of the blade is such that an entire strip of TM is removed without leaving TM leaflets behind and without causing collateral damage to adjacent tissues.

RELATED APPLICATIONS

The present application is a continuation of Ser. No. 15/791,204, filedOct. 23, 2017, which is a continuation-in-part of U.S. patentapplication Ser. No. 15/207,329, filed on Jul. 11, 2016, which issued asU.S. Pat. No. 9,872,799 on Jan. 23, 2018, which is acontinuation-in-part of U.S. patent application Ser. No. 14/375,350filed on Jul. 29, 2014, which issued as U.S. Pat. No. 10,327,947 on Jun.25, 2019, which is a national stage entry of PCT Application No.PCT/US13/37374 filed on Apr. 19, 2013, which claims the benefit of U.S.Provisional Patent Application No. 61/637,611 filed on Apr. 24, 2012,each of which is incorporated herein by reference.

BACKGROUND

There are numerous medical and surgical procedures in which it isdesirable to cut and remove a strip of tissue of controlled width fromthe body of a human or veterinary patient. For example, it may sometimesbe desirable to form an incision of a controlled width (e.g., anincision that is wider than an incision made by a typical scalpel,cutting blade or needle) in the eye, skin, mucous membrane, tumor, organor other tissue or a human or animal. In addition, it may sometimes bedesirable to remove a strip or quantity of tissue from the body of ahuman or animal for use as a biopsy specimen, for chemical/biologicalanalysis, for retention or archival of DNA identification purposes, etc.In addition, some surgical procedures require removal of a strip oftissue of a known width from an anatomical location within the body of apatient.

One surgical procedure wherein a strip of tissue of a known width isremoved from an anatomical location within the body of a patient is anophthalmological procedure used to treat glaucoma. This ophthalmologicalprocedure is sometimes referred to as a goniotomy. In a goniotomyprocedure, a device that is operative to cut or ablate a strip of tissueof approximately 2-10 mm in length or more and about 50-230 μm in widthis inserted into the anterior chamber of the eye and used to remove afull thickness strip of tissue from the trabecular meshwork. Thetrabecular meshwork is a loosely organized, porous network of tissuethat overlies a collecting canal known as Schlemm's canal. A fluid,known as aqueous humor, is continually produced in the anterior chamberof the eye. In healthy individuals, aqueous humor flows through thetrabecular meshwork, into Schlemm's canal and out of the eye through aseries of ducts called collector channels. In patients who suffer fromglaucoma, the drainage of aqueous humor from the eye may be impaired byelevated flow resistance through the trabecular meshwork, therebyresulting in an Increase in intraocular pressure. The goniotomyprocedure can restore normal drainage of aqueous humor from the eye byremoving a full thickness segment of the trabecular meshwork, thusallowing the aqueous humor to drain through the open area from which thestrip of trabecular meshwork has been removed.

SUMMARY

Embodiments of the present disclosure can be used for surgical medicinalintervention. For example, some embodiments relate to a microsurgicaldevice and methods of its use for treatment of various medicalconditions including but not limited to eye diseases, such as glaucoma,using minimally invasive surgical techniques. Specifically, the devicemay be a dual-blade device for cutting the trabecular meshwork (“TM”) inthe eye. In particular, the device may have a device tip providing entryinto the Schlemm's canal via its size (i.e., for example, betweenapproximately 0.2-0.3 mm width) and a configuration where the entryblade tip ramps upwardly providing a wedge or ramp-like action forcutting the TM.

To facilitate the understanding of the present disclosure, a number ofterms are defined below.

Terms defined herein have meanings as commonly understood by a person ofordinary skill in the areas relevant to the present disclosure. Termssuch as “a,” “an,” and “the” are not intended to refer to only asingular entity, but include the general class of which a specificexample may be used for illustration.

As used herein, the term “patient” or “subject” refers to a livingmammalian organism, such as a human, monkey, cow, sheep, goat, dog, cat,mouse, rat, guinea pig, or transgenic species thereof. In certainembodiments, the patient or subject is a primate. Non-limiting examplesof human subjects are adults, juveniles, infants and fetuses.

“Prevention” or “preventing” includes: (1) inhibiting the onset of adisease in a subject or patient which may be at risk and/or predisposedto the disease but does not yet experience or display any or all of thepathology or symptomatology of the disease, and/or (2) slowing the onsetof the pathology or symptomatology of a disease in a subject or patientwhich may be at risk and/or predisposed to the disease but does not yetexperience or display any or all of the pathology or symptomatology ofthe disease.

The term “therapeutically effective amounts” or “pharmaceuticallyeffective amounts”, as used herein means that amount which, whenadministered to a subject or patient for treating a disease, issufficient to effect such treatment for the disease or to ameliorate oneor more symptoms of a disease or condition (e.g. ameliorate pain).

As used herein, the terms “treat” and “treating” are not limited to thecase where the subject (e.g. patient) is cured and the disease iseradicated. Rather, embodiments of the present disclosure alsocontemplate treatment that merely reduces symptoms, improves (to somedegree) and/or delays disease progression. It is not intended thatembodiments of the present disclosure be limited to instances wherein adisease or affliction is cured. It is sufficient that symptoms arereduced.

As used herein “goniotomy” refers to a surgical procedure primarily usedto treat various types of glaucoma (ex, primary open angle glaucoma).

As used herein “trabecular meshwork” refers to area of tissue in the eyelocated around the base of the cornea, near the ciliary body, (betweenthe scleral spur and Schwalbe's line) and is responsible for drainingthe aqueous humor from the eye via the anterior chamber (the chamber onthe front of the eye covered by the cornea). The tissue is spongy andlined by trabeculocytes; it allows fluid to drain into a circularchannel in the eye called Schlemm's canal and eventually flowing intothe blood system.

As used herein “Schlemm's canal” refers to a circular channel in the eyethat collects aqueous humor from the anterior chamber and delivers itinto the bloodstream via the collector channels and anterior ciliaryveins.

As used herein “eye diseases” refers to various conditions of the eyeincluding, but not limited to Glaucoma—optic neuropathy, Glaucomasuspect—ocular hypertension, Primary open-angle glaucoma, Primaryangle-closure glaucoma, primary open angle glaucoma, normal or lowtension glaucoma, pseudoexfoliation glaucoma, pigment dispersionglaucoma, angle closure glaucoma (acute, subacute, chronic), neovascularor inflammatory glaucoma, ocular hypertension, and other types ofglaucoma that are related to dysregulation of intraocular pressure.

As used herein “hypotony” refers to reduced intraocular pressure. Thestatistical definition of hypotony is intraocular pressure (“TOP”) lessthan 6.5 mmHg, which is more than 3 standard deviations below the meanTOP. The clinical definition of hypotony is TOP low enough to result inpathology (vision loss). The vision loss from low TOP may be caused bycorneal edema, astigmatism, cystoid macular edema, maculopathy, or othercondition. Hypotony maculopathy is characterized by a low TOP associatedwith fundus abnormalities, including chorioretinal folds, optic nervehead edema in the acute setting, and vascular tortuosity.

As used herein “Schwalbe's line” refers to the anatomical line found onthe interior surface of the eye's cornea, and delineates the outer limitof the corneal endothelium layer. Specifically, it represents thetermination of Descemet's membrane.

As used herein “Descemet's membrane” refers to the basement membranethat lies between the corneal proper substance, also called stroma, andthe endothelial layer of the cornea.

As used herein “scleral spur” refers to an annular structure composed ofcollagen in the human eye, a protrusion of the sclera into the anteriorchamber. It is the origin of the longitudinal fibers of the ciliarymuscle and is attached anteriorly to the trabecular meshwork. Open-angleglaucoma (OAG) and closed-angle glaucoma (CAG) may be treated bymuscarinic receptor agonists (e.g., pilocarpine), which cause rapidmiosis and contraction of the ciliary muscles, this pulls the scleralspur and results in the trabecular meshwork being stretched andseparated. This opens the fluid pathways and facilitates drainage of theaqueous humour into the canal of Schlemm and ultimately decreasingintraocular pressure.

As used herein “Trabectome®” refers to a minimally invasive glaucomasurgical electrosurgical or ablation tool for the surgical management ofadult, juvenile and infantile glaucoma. Unlike a trabeculectomy, thesurgery with a Trabectome® should not create an external filtering blebor require leaving a permanent hole in the eye. Instead, the Trabectome®electro-surgical handpiece opens access to the eyes natural drainagesystem.

Embodiments of the present disclosure are illustrated, for example,according to various aspects described below.

According to some embodiments, disclosed is a device for incising atrabecular meshwork, the device comprising a platform for elevating aportion of the trabecular meshwork away from an outer wall of aSchlemm's canal, the platform comprising a tip at a distal side of theplatform and a top surface extending from the distal side to a proximalside of the platform, opposite the distal side of the platform, firstand second sides extending from the top surface, wherein the first andsecond sides are parallel to each other, first and second lateralelements for creating first and second incisions through the trabecularmeshwork, the first and second lateral elements extending from theproximal side of the platform; and a bottom surface, opposite the topsurface, wherein the bottom surface comprises first and secondprotrusions separated by a gap and a planar portion adjacent the tip,wherein the tip is separated from the gap by the planar portion.

According to some embodiments, disclosed is a device for incising atrabecular meshwork, the device comprising a platform for elevating aportion of the trabecular meshwork away from an outer wall of aSchlemm's canal, the platform comprising a tip at a first end of theplatform and a top surface extending from the first end to a second endof the platform, first and second lateral elements for creating firstand second incisions through the trabecular meshwork, the first andsecond lateral elements extending from the second end of the platform,and a bottom surface, opposite the top surface, wherein the bottomsurface comprises first and second protrusions separated by a gap and aplanar portion adjacent the tip, wherein the tip is separated from thegap by the planar portion.

According to some embodiments, disclosed is a method of incising atrabecular meshwork, the method comprising inserting the tip of a devicefor incising trabecular meshwork into a Schlemm's canal of an eye,placing the bottom surface of the device into contact with an outer wallof the Schlemm's canal, moving the device along a portion of theSchlemm's canal, creating first and second incisions through thetrabecular meshwork with the first and second lateral elements,receiving a portion of Schlemm's canal tissue into the gap between thefirst and second protrusions.

Additional features and advantages of the subject technology will be setforth in the description below, and in part will be apparent from thedescription, or may be learned by practice of the subject technology.The advantages of the subject technology will be realized and attainedby the structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the subject technology asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding of the subject technology and are incorporated in andconstitute a part of this description, illustrate aspects of the subjecttechnology and, together with the specification, serve to explainprinciples of the subject technology.

FIG. 1 shows a representative histologic specimen of human anteriorchamber angle structures following incision with a microvitreoretinal(“MVR”) blade. The incision extends through full-thickness trabecularmeshwork and the Schlemm's canal and into adjacent sclera (black arrowhead). A large portion of trabecular meshwork remains on either side ofthe incision (black arrows). An asterisk labels the Schlemm's canal.Light micrograph, hematoxylin-eosin, magnification ×100.

FIG. 2 shows a representative histologic specimen of human anteriorchamber angle structures following incision with a Trabectome®. Theincision extends through the full-thickness of a trabecular meshworkwithout damage to adjacent sclera. A portion of trabecular meshwork hasbeen removed centrally with a moderate amount of residual tissue oneither side of the incision (black arrows). Charring of the incisionedges is noted. An asterisk labels the Schlemm's canal. SS=scleral spur.Light micrograph, hematoxylin eosin, magnification ×100.

FIG. 3 shows a representative histologic specimen of human anteriorchamber angle structures following an incision with a dual blade device.The incision extends through the full-thickness of a trabecular meshworkwithout injury to adjacent sclera. A near-complete removal of trabecularmeshwork tissue has been accomplished (black arrows). An asterisk labelsthe Schlemm's canal. SS=scleral spur. Light micrograph,hematoxylin-eosin, magnification ×100.

FIG. 4 shows one embodiment of the dual blade device for treatment ofglaucoma. The device is illustrated to reveal the dual cutting blades(black arrows) as well as the distal point (asterisk) that is designedto pierce the trabecular meshwork (“TM”) and enter into the Schlemm'scanal. Once in the canal, the device is advanced so that the TM moves upthe ramp from the distal point toward the dual cutting blades, whichthen cleanly incise the presented TM. The distance between the dualblades is designed to closely match that of the width of the TM across arange of human eyes. The inset is a photo of the first prototype devicethat was made of medical-grade stainless steel.

FIG. 5 shows four different angles of a fabricated embodiment of thepresent disclosure under 40× magnification.

FIG. 6 shows two different angles of a fabricated embodiment of thepresent disclosure under 40× magnification. A size scale indicatesproportions.

FIG. 7 shows a side angle of a fabricated embodiment of the presentdisclosure under 40× magnification. A size scale indicates proportions.

FIG. 8 shows an angled, side view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform.

FIG. 9 shows an angled, side view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform. Measurements of specific parts are indicated.

FIG. 10 shows a front face view of one embodiment of the device with anenlarged detailed view of the operative end of the device with thebeveled platform.

FIG. 11 shows a front face view of one embodiment of the device with anenlarged detailed view of the operative end of the device with thebeveled platform 5. Measurements of specific parts are indicated.

FIG. 12 shows a front face view of one embodiment of the device with anenlarged detailed view of the operative end of the device with thebeveled platform 5. Shown are examples of the different angles ofattachment of the handle 1 to the beveled platform 5 relative to theZ-axis. The increased platform thickness as the platform extends fromthe insertion tip 6 towards the back of the platform 7 is alsoindicated.

FIG. 13 shows a straight top view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform 5.

FIG. 14 shows a straight top view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform 5. Measurements of specific parts are indicated.

FIG. 15 shows an angled, side view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform 5. The shaded aspect provided a view of the dimensionsof the beveled platform. The angle of tool shaft 4 attachment and offirst and second blade attachment relative to the beveled platform 5 areindicated.

FIG. 16 shows an angled, side view of one embodiment of the device withan enlarged detailed view of the operative end of the device with thebeveled platform 5. The shaded aspect provided a view of the dimensionsof the beveled platform. Measurements of specific parts are indicated.

FIG. 17 shows a front face view of one embodiment of the device with anenlarged detailed view of the operative end of the device with thebeveled platform 5. Shown are examples of the different angles ofattachment of the handle 1 to the beveled platform 5 clockwise 0, 15,and 30 degrees relative to the Z-axis and X-axis. The increased platformthickness is also indicated as the platform extends from the insertiontip 6 towards the back of the platform 7 and from the first side (on theright) to the second side (on the left).

FIG. 18A shows a front face view of one embodiment of the device with anenlarged detailed view of the operative end of the device with thebeveled platform 5. Shown are examples of the different angles ofattachment of the handle 1 to the beveled platform 5 counterclockwise 0,15, and 30 degrees relative to the Z-axis and X-axis. The increasedplatform thickness is also indicated as the platform extends from theinsertion tip 6 towards the back of the platform 7 and from the secondside (on the left) to the first side (on the right).

FIG. 18B shows one possible version of the device wherein it isintegrated onto an endoscope.

FIG. 19A shows a device applied to a trabecular meshwork and Schlemm'scanal, according to some embodiments of the present disclosure.

FIG. 19B shows a device elevating the trabecular meshwork away from theSchlemm's canal, according to some embodiments of the presentdisclosure.

FIG. 19C shows a device incising the trabecular meshwork, according tosome embodiments of the present disclosure.

FIG. 19D shows a device engaging a strip of trabecular meshwork,according to some embodiments of the present disclosure.

FIG. 20 shows an incision in trabecular meshwork extending into sclerawith large segments of trabecular meshwork still present. FIG. 20 showsdamage to sclera below Schlemm's canal by the blade.

FIG. 21 shows post-Trabectome® treatment showing trabecular meshworkremnants and charring of tissue. Tissue debris is occluding a collectorchannel. FIG. 21 shows thermal damage to the TM. For the Trabectome®procedure (designed to replace goniotomy and to improve upon thatprocedure by removing sections of trabecular meshwork) a Trabectome®device was used to engage the trabecular meshwork and cautery wasapplied to the trabecular meshwork. The circle shows an area where asmall segment of trabecular meshwork was removed; however, there arelarge leaflets of trabecular meshwork remaining and charred tissue oneither side of the treatment area. In this previous methodology, thedevice “burns” tissue and the burning of tissue creates inflammationthat leads to more scar formation that leads to failure of thesurgically induced opening into Schlemm's canal. In addition, due toablation, many bubbles are formed during this procedure, which makesvisualization difficult during the actual procedure. These issues do notoccur with embodiments of the present disclosure. A representative photoof the Trabectome® is in FIG. 21

FIG. 22 shows tissue after treatment with a device according toembodiments of the present disclosure. FIG. 22 shows no damage tostructures adjacent to the normal location of TM. FIG. 22 shows completeremoval of TM tissue with no remaining leaflets of TM.

FIG. 23 shows another description of the configuration of the dual bladedevice according to embodiments of the present disclosure.

FIG. 24 shows a side view of an exemplary device according toembodiments of the present disclosure.

FIG. 25 shows a front view of the device of FIG. 25 according toembodiments of the present disclosure.

FIG. 26 shows a front view of the device of FIG. 25 according toembodiments of the present disclosure.

FIG. 27 shows a front view of the device of FIG. 25 according toembodiments of the present disclosure.

FIG. 28 shows a front view of the device of FIG. 25 according toembodiments of the present disclosure.

FIG. 29 shows the anatomy of interest at a cross section of the eye. Thehandle 1 is in the eye and going across to the opposite side Schlemm'scanal outlined by a circle. The angle between the handle 1 and the rampwill allow the blade to enter Schlemm's canal and cut tissue. That firstangle would make the ramp come out towards the viewer. However, a secondangle would also need to exist that follows the black lines to allow thedevice to also fit in the angles space of Schlemm's canal.

DETAILED DESCRIPTION

In the following detailed description, specific details are set forth toprovide an understanding of the subject technology. It will be apparent,however, to one ordinarily skilled in the art that the subjecttechnology may be practiced without some of these specific details. Inother instances, well-known structures and techniques have not beenshown in detail so as not to obscure the subject technology.

There are several practical advantages of a dual blade device, ascontemplated herein, for use in goniotomy. First, a dual blade devicemay be reusable and can be added to a standard cataract surgical tray.Second, the lack of moving parts or the need for coupled irrigation or aseparate power source allows for inexpensive manufacturing and rapidacquisition of surgical expertise. This would permit easy, economicalaccess to a new technique, especially in underserved locations aroundthe world. The simple design and material requirements of dual-bladedevice embodiments would be more economical. Finally, in contrast toother techniques for TM removal, embodiments of dual-blade devicedesigns conform to the Schlemm's canal anatomy, minimize damage toadjacent tissues, and provide excellent control over excised tissue.Therefore, the presented dual-blade minimally invasive glaucoma surgery(“MIGS”) device represents a novel technique to perform a goniotomy withor without concomitant cataract extraction. In some embodiments, thedual-blade devices are capable of a more complete removal of TM tissuefrom the anterior chamber angle in a simple and inexpensive manner ascompared to conventional devices. Perfusion eye studies support thepotential for significant IOP reduction with this technique.

Glaucoma is believed to be one of the leading causes of blindnessworldwide. It has been reported that a modifiable disease risk factor isintraocular pressure (“TOP”). Conventional treatment has centered onlowering IOP pharmaceutically with hypotensive medications or surgicallythrough the use of lasers or incisional procedures. The main area ofobstruction to aqueous outflow, with subsequent dysregulation of IOP, isthought to be located at the juxtacanalicular trabecular meshwork (“TM”)and distal outflow structures. Performing a goniotomy or trabeculotomyin adults with glaucoma has not been associated with great success inlowering IOP. In contrast, these procedures have been reported to bemore successful in congenital glaucoma, where a membrane covering the TMis thought to be a major factor in impedance of aqueous outflow. Morerecently, there have been attempts to use ab interno trabeculectomyprocedures to remove TM in adult patients and results have been mixed.

One reason for poor long-term outcomes with this approach in adultsmight be related to incomplete removal of TM and membrane formationacross the remaining TM leaflets with subsequent elevation in IOP. It isunclear how a more complete removal of TM tissue might compare toprocedures that simply incise TM, such as a single incision goniotomy,or procedures that cauterize TM with tissue removal, such as Trabectome®(Neomedix, Tustin, Calif., USA). The dual-blade device is specificallydesigned to conform to the drainage angle anatomy of the human eye. Thedevice can be used to perform a dual incision goniotomy by engaging TMand cutting the target tissue while minimizing leaflets left in placeand damage to adjacent tissues. The device was designed and manufacturedat the University of Colorado Eye Center. Tissue effects from the deviceare compared to those from a single incision goniotomy using amicrovitreoretinal (“MVR”) blade (BD, Franklin Lakes, N.J., USA) andcautery of TM with the Trabectome® device. Human eye perfusion studieswere also completed to assess the IOP-lowering efficacy of eachapproach.

Recently, there has been a growing trend toward innovations in MIGS. Therisks and imperfections of guarded filtration surgery and tube shuntprocedures have driven this paradigm shift despite the proven long-termefficacy of these incisional procedures. Drawbacks of traditionalincisional procedures include unpredictable IOP-lowering results,prolonged visual recovery, long-term risk of infection and vision loss,frequency of follow-up visits, and long-term failure rate. Proceduressuch as endoscopic cyclophotocoagulation, ab interno trabeculectomy withTrabectome®, and canaloplasty with the iScience illuminated catheter(iScience, Menlo Park, Calif., USA) were all introduced to addresslimitations of full-thickness surgery, most notably to eliminate thepresence of a filtering bleb. However, a major drawback of all of theseprocedures is the additional equipment cost required and, in some cases,a steep learning curve. The added equipment cost in particular presentsa significant hurdle to providers, hospitals, and surgery centers thatmay require several procedures to recoup the initial investment.Providers and patients may also face opposition from insurance companiesregarding coverage of a procedure lacking long-term efficacy data. Therequirement for additional equipment also limits patient access to theseprocedures in underserved areas of the world.

A goniotomy is generally referred to as a surgical procedure used totreat glaucoma. Glaucoma can be caused by blockage in the trabecularmeshwork and/or a developmental arrest of some of the structures withinthe anterior (front) segment of the eye. These changes lead to an excessof fluid in the eye, which can cause pressure that can damage theinternal structures of the eye leading to optic neuropathy and loss ofvision.

One type of glaucoma that can be treated with goniotomy is known ascongenital glaucoma. Congenital glaucoma is caused by a decrease in oreven a complete obstruction of the outflow of intraocular fluid. Theocular syndromes and anomalies that predispose a child to congenitalglaucoma include the following: Reiger's anomaly; Peter's anomaly;Axenfeld's syndrome; and Axenfeld-Rieger's syndrome. Systemic disordersthat affect the eyes in ways that may lead to glaucoma include Marian'ssyndrome; rubella (German measles); and the phacomatoses, which includeneurofibromatosis and Sturge-Weber syndrome. Since these disordersaffect the entire body as well as the eyes, the child's pediatrician orfamily doctor will help to diagnose and treat these diseases.

One purpose of a goniotomy is to clear the obstruction to aqueousoutflow from the eye, which in turn lowers the intraocular pressure(“TOP”). This is a treatment method for any type of glaucoma includingprimary open angle glaucoma and chronic angle closure glaucoma.

Before the surgeon begins the procedure, the patient may be givenmiotics, which are drugs that cause the pupil to contract. The partialclosure may improve the surgeon's view of and access to the trabecularmeshwork; it may also protect the lens of the eye from trauma duringsurgery. Other drugs may be administered to lower the intraocularpressure. Goniotomy procedures may be done without use of miotics. Insome embodiments, devices may be used in the setting of a dilated(non-miotic) pupil, as can devices described as prior art.

Once the necessary drugs have been given and the patient isanesthetized, the surgeon may use forceps or sutures to stabilize theeye in the correct position. The patient's head may be rotated away fromthe surgeon so that the interior structures of the eye are more easilyseen. Next, with either a knife-needle or a goniotomy knife, the surgeonpunctures the cornea while looking at the interior of the eye through amicroscope or a loupe. An assistant may use a syringe to introduce fluidinto the eye's anterior chamber through a viscoelastic tube as thesurgeon performs the goniotomy.

A gonioscopy lens may be then placed on the eye. As the eye is rotatedby an assistant, the surgeon sweeps the knife blade or needle through90-120 degrees of arc in the eye, making incisions in the anteriortrabecular meshwork, avoiding the posterior part of the trabecularmeshwork in order to decrease the risk of damage to the iris and lens.Endoscopic visualization may also be used to guide cutting. In someembodiments, devices may be placed at the end of an endoscope,precluding the need for a gonio lens during treatment.

Once the knife and tubing are removed, saline solution may be introducedthrough the hole to maintain the integrity of the eye and the hole isclosed with sutures. The surgeon then applies antibiotics andcorticosteroids to the eye to prevent infection and reduce inflammation.The head may be then rotated away from the incision site so that bloodcannot accumulate. The second eye may be operated on at the same time.If the procedure needs to be repeated, another area of the eye may betreated.

At present there remains a need in the art for the development ofsimple, inexpensive and accurate instruments useable to perform theprocedure of cutting the TM in the eye and effectively remove a completefull thickness strip of TM without leaving TM leaflets as well as otherprocedures where it is desired to remove a strip of tissue from a largermass of tissue.

A goniotomy is simply an incision of the TM to cut it into two leaflets,it is the basic form of cutting TM that all other devices are trying toimprove upon. Since it is just an incision, it leaves the entire tissuebehind (albeit segmented) and then the tissue scars down and the eyepressure goes up anyway. This may be why “newer” devices are trying tocut and remove the actual TM from the area over Schlemm's canal. Thecomplete removal of TM without leaving leaflets is one key featuredifferentiating embodiments of the present disclosure from conventionalblade goniotomy (e.g., using an MVR blade). The anatomical design of thedevice of the present disclosure may be better suited for effectiveremoval of complete strips of tissue, in particular the TM, with minimalto no traumatic impact on the surrounding tissue.

Specific advantages of some embodiments described herein as compared toother conventional devices include but are not limited to:

1. No mechanically moving parts

2. No cautery or burning of tissue

3. Two blades are in place on the sides of the device that cut thetrabecular meshwork (TM) in a precise fashion leaving little TM behind(current devices leave a lot of TM behind that then scars over)

4. The entry into Schlemm's canal is done with use of the blade tipsimilar to what has been described for decades in standard goniotomy.Other devices use a non-blade footplate to enter Schlemm's canal.

5. The dimensions of the device allow for complete cutting and fit inSchlemm's canal with precision.

6. The tip of the blade ramps up to the two side blades to present theTM to the two slide blades, which then allows for more precise cutting.

7. The sides of the ramp are devoid of blades or cutting features untilthe point where the dual blades are present.

8. Cutting of the TM with the dual blades occurs at points elevated fromthe natural resting position of the TM.

In some embodiments, a device comprises: a handle 1, interface of toolshaft and handle 2, a tool shaft 3, interface of tool shaft and beveledplatform 4, beveled platform 5, a first end/beveled platformtip/insertion blade tip 6, a second end/back of the beveled platform 7,a first side 8, a second side 9, a first blade 10, and a second blade11.

In some embodiments, a device 12 comprises: a handle 1 that necks downto a tool shaft 3 by a first interface 2 wherein said tool shaft widensinto a beveled platform 5 by a second interface 4, wherein said beveledplatform 5 comprises a insertion blade tip 6 on a distal end of thebeveled platform 5 comprising a ramp 13 from said insertion blade tipback towards the posterior end the beveled platform 5, and a firstlateral element (e.g., blade) 10 and second lateral element (e.g.,blade) 11 along the sides of said beveled platform 5. In someembodiments, said sides of said beveled platform 5 comprise a first side8 and a second side 9. In some embodiments, the platform 5 includes afirst side 8 extending from the proximal side of the platform 5 to thedistal side of the platform 5 and a second side 9 extending from theproximal side of the platform 5 to the distal side of the platform 5. Insome embodiments, the first side 8 and the second side 9 each form abevel of the platform 5. In some embodiments, the first side 8 and thesecond side 9 each form a convex portion of the platform 5. In someembodiments, proximal segments of the first side 8 and the second side 9are parallel to each other and distal segments of the first side 8 andthe second side 9 intersect at the tip 6. In some embodiments, the firstlateral element extends from the first side and the second lateralelement extends from the second side.

In some embodiments, said first lateral blade 10 and second lateralblade 11 are in a perpendicular alignment to the bottom of the beveledplatform. In some embodiments, the first and second lateral blades 10,11 are straight. In some embodiments, the first and second lateralblades 10, 11 are parallel to each other.

In some embodiments, the ramp 13 increases from a distal width at thedistal side (e.g., at the tip 6) to a proximal width, greater than thedistal width, at the proximal side (e.g., adjacent to the lateral blades10, 11). The ramp 13 can be planar, concave, and/or convex. Where theramp 13 is planar, it can provide a gradual stretching of TM that iselevated by the platform 5 and across the ramp 13. In some embodiments,a maximum width across the first and second lateral elements is not lessthan a maximum width across the ramp. This allows the incisions to bemade at the outer peripheries of the platform, where the first side 8and the second side 9 elevate and present the TM to the lateral blades10, 11.

In some embodiments, the device 12 includes a bottom surface 15 that isconfigured to abut the outer wall of the Schlemm's canal 22 during aprocedure. The bottom surface 15 can be planar, convex, concave, orcombinations thereof. For example, the bottom surface 15 can include aconcave portion between at least two lateral edges. For example, lateraledges can be provided below the first side 8 and the second side 9 ofthe ramp 13, with a concave portion formed between the lateral edges.The lateral edges can make contact with the outer wall of the Schlemm'scanal 22 during a procedure.

In some embodiments, a device 12 comprises a handle 1 and a beveledplatform 5, wherein said platform 5 is set at a specific angle andorientation relative to said handle 1. In some embodiments, a device 12comprises a handle 1 and a beveled platform 5, wherein said platform 5freely rotates in at least two dimensions. In some embodiments, saidhandle 1 and beveled platform 5 are operably attached at an angleranging between 90 and 120 degrees in the Y-Z axis (shown in FIG. 15).In some embodiments, said handle 1 and beveled platform 5 are operablyattached at an angle ranging between 90 and 180 degrees in the X-Z axis(shown in FIG. 10). In some embodiments, said platform 5 freely rotatesin an X-Y dimension relative to said handle 1. In some embodiments, saidplatform 5 remains at a fixed angle in the X-Y, X-Z, and Y-Z dimensionsrelative to said handle 1 (shown in FIG. 15). In some embodiments, saidplatform 5 freely rotates in a positive Z dimension relative to saidhandle 1.

In some embodiments, said beveled platform 5 comprises a firstend/beveled platform tip/insertion blade tip 6 and a second end/back ofthe beveled platform 7, wherein said second end/back of the beveledplatform 7 is between 2 and 30 times greater in thickness relative tosaid first end/beveled platform tip/insertion blade tip 6. The thicknesscan be measured along the Z-axis, such as through a surface of the ramp13 and the base of the platform 5. In some embodiments, the dimensionsof the beveled platform 5 are dictated by the formula A²+B²=C², whereinA is the length of said beveled platform 5 from said insertion blade tip6 to the back of the beveled platform 7, B is the height of the beveledplatform 5 and C is the length of the ramp formed by the beveledplatform insertion blade tip up to the height of said beveled platform.In some embodiments, the height of said beveled platform 5 is not toexceed 0.5 millimeters. In some embodiments, the length of said beveledplatform 5 from said insertion blade tip 6 to the back of the beveledplatform 7 is not to exceed 1.0 millimeters. In some embodiments, thewidth of said beveled platform 5 is not to exceed 0.35 millimeters. Insome embodiments, said first end/beveled platform tip/insertion bladetip 6 comprises a fine surgical lancet. In some embodiments, said firstend/beveled platform tip/insertion blade tip 6 comprises an angle ofbetween 20 and 90 degrees. In some embodiments, said beveled platform 5increases in thickness from a fine blade tip towards the second end/backof the beveled platform 7 in the direction of the Y-axis.

In some embodiments, said first end/beveled platform tip/insertion bladetip 6 comprises a pointed tip with fine edges of surgical sharpness. Insome embodiments, said first end/beveled platform tip/insertion bladetip 6 comprises a lancet. In some embodiments, said beveled platform 5further comprises a first blade 10 and a second blade 11. In someembodiments, said first blade 10 is attached to a first side 8 of saidsecond end/back of the beveled platform 7. In some embodiments, saidfirst blade 10 and beveled platform 5 are operably attached at an angleranging between 90 and 180 degrees in the Y-Z axis (shown in FIG. 15).In some embodiments, said angle is preferably between 90 and 120 degreesin the Y-Z axis (shown in FIG. 15). In some embodiments, said secondblade 11 and beveled platform 5 are operably attached at an angleranging between 90 and 120 degrees in the Y-Z axis (shown in FIG. 15).In some embodiments, said first blade 10 and handle 1 are operablypositioned at an angle ranging between 90 and 120 degrees in the Y-Zaxis (shown in FIG. 15). In some embodiments, said second blade 11 andhandle 1 are operably positioned at an angle ranging between 90 and 120degrees in the Y-Z axis (shown in FIG. 15). In some embodiments, saidsecond blade 11 is attached to a second side 9 of said second end/backof the beveled platform 7. In some embodiments, said beveled platform 5increases in thickness from said second side 9 towards the first side 8in the direction of the X-axis (shown in FIG. 17). In some embodiments,said beveled platform 5 increases in thickness from said second side 9towards the first side 8 in the direction of the X-axis and said beveledplatform 5 increases in thickness from a fine blade tip of the first end6 towards the second end/back of the beveled platform 7 in the directionof the Y-axis (shown in FIG. 17). In some embodiments, said beveledplatform 5 increases in thickness from said first side 8 towards thesecond side 9 in the direction of the X-axis (shown in FIG. 18). In someembodiments, said beveled platform 5 increases in thickness from saidfirst side 8 towards the second side 9 in the direction of the X-axisand said beveled platform 5 increases in thickness from a fine blade tipof the first end 6 towards the second end/back of the beveled platform 7in the direction of the Y-axis (shown in FIG. 18). In some embodiments,said first blade 10 and said second blade 11 are parallel (shown in FIG.15). In some embodiments, said first blade 10 and said second blade 11extend above the top surface of said second end/back of the beveledplatform 7. In some embodiments, said first blade 10 and said secondblade 11 are positioned at an angle between approximately 100 to 140degrees relative to the top surface of said second end/back of thebeveled platform 7 (shown in FIG. 15). In some embodiments, said beveledplatform 5 is approximately 0.3 millimeters wide. In some embodiments,said beveled platform 5 is approximately 0.2 millimeters wide. In apreferred embodiment, said beveled platform 5 is approximately 0.25millimeters wide. In some embodiments, said beveled platform 5 isapproximately 1.0 millimeters long. In some embodiments, said beveledplatform 5 is approximately 0.4 millimeters high. In some embodiments,said highest point on the beveled platform 5 is the first and secondblades. The device 12 (shown in FIG. 8, FIG. 10, FIG. 13, and FIG. 15)may be provided as a pre-sterilized, single-use disposable probe or tipthat is attachable to a standard surgical handpiece.

It is not intended that embodiments of the present disclosure be limitedto any particular construction material; however, it is believed thatpreferred materials include titanium, stainless steel, polyether etherketone (PEEK), shape memory alloy, and shape memory polymers. In someembodiments, the present device is made from metal alloy materials. Insome embodiments, the device of the present disclosure is rigid at roomtemperature, but is more flexible at body temperature. In someembodiments, the portions of the device of the present disclosure arerigid at room temperature, but are more flexible at body temperature. Insome embodiments, portions of the device are made from differentmaterials. In some embodiments, portions of the device are made frommaterials of various rigidity. In some embodiments, said tool shaft isflexible. In some embodiments, said tool shaft is made from a lowerdensity material.

It is not intended that embodiments of the present disclosure be limitedto any particular construction material; however, it is believed thatpreferred materials include titanium, stainless steel, polyether etherketone (PEEK), shape memory alloy, and shape memory polymers. In someembodiments, the device of the present disclosure is rigid at roomtemperature, but is more flexible at body temperature. In someembodiments, the portions of the device of the present disclosure arerigid at room temperature, but are more flexible at body temperature. Insome embodiments, portions of the device are made from differentmaterials. In some embodiments, portions of the device are made frommaterials of various rigidity. In some embodiments, said tool shaft isflexible. In some embodiments, said tool shaft is made from a lowerdensity material.

The tip may be formed of various metals or polymers that are rigidenough to support elevation of tissue such as TM. The blades may be madeof the same materials as the distal tip and handle 1 or might be of aseparate material that allows for greater tolerances for a razor edge(stainless steel or titanium). Shape memory polymers or alloys could beutilized to enhance functionality of the device by allowing for a changein confirmation after placing the device in the eye and exposing it tobody heat. A movable sheath might be employed to cover the distalcutting tip during the insertion and removal steps from the eye so thatthe tip is not injured by movement across the clear corneal wound.

The device can be made of different colors such as blue or black so thatit can be visualized through the semi translucent TM tissue for betterguidance.

According to some embodiments, devices disclosed herein can be used forincising tissue, such as a trabecular meshwork. A device may beintroduced through a clear corneal incision (incision size between 0.5and 2.8 mm in width) and advanced through the anterior chamber eitheracross the pupil or across the body of the iris to engage the trabecularmeshwork (TM) on the opposite side of the anterior chamber. The anteriorchamber may be filled with viscoelastic to stabilize the chamber duringthe procedure. As shown for example in FIG. 19A, once the target tissue20 (e.g., TM) is reached, the tip 6 of the device may be then used toenter into Schlemm's canal (“SC”) 22.

According to some embodiments, for example as shown in FIG. 19A, theramp 13 may be used to elevate the TM 20 away from the outer wall of theSchlemm's canal 22. According to some embodiments, for example as shownin FIG. 19B, the advancement of the platform 5 can stretch the TM 20 asit travels up the ramp 13 without tearing a strip 20 a of the TM 20 thatis on the ramp 13. For example, the first side 8 and the second side 9can allow the TM 20 on the ramp 13 (e.g., distal to the first and secondlateral blades 10, 11) to remain connected to the TM 20 that is notelevated by the ramp 13. As the TM 20 is elevated, it is under tensionthat is greater than the tension of the TM 20 when not elevated from theSC 22. Advancement of the ramp 13 facilitates presentation of the TM 20to the first and second lateral blades 10, 11. According to someembodiments, for example as shown in FIG. 19C, the TM 20 contacts thefirst and second lateral blades 10, 11 while the TM 20 is elevated(e.g., stretched and/or under tension). In this configuration, the firstand second lateral blades 10, 11 incise first and second incisions intothe TM 20 to form the strip 20 a of the TM 20. The incision is moreeasily and precisely made due to the elevation of the TM 20. Duringadvancement of the platform 5, at least a portion of the strip 20 a canbe received within the gap 14 between the first and second lateralblades 10, 11. The strip 20 a can have a width W that corresponds to thedistance D across the gap 14. The width W can be measured along theX-axis, such as across the first and second incisions and transversely(e.g., orthogonally) to the direction of advancement of the device 12 toform the strip 20 a. The distance D can be measured along the X-axis,such as across the first and second lateral blades 10, 11 andtransversely (e.g., orthogonally) to the direction of advancement of thedevice 12 to form the strip 20 a. According to some embodiments, forexample as shown in FIG. 19D, the strip 20 a that has been separatedfrom a remainder of the TM 20 can be removed by a device 30 (e.g.,forceps) or by aspiration.

The advancement of the platform 5 and the ramp 13 can proceed as thedevice advances clockwise or counterclockwise. The distal cuttingportion is angled so that the dual blades are placed in optimum cuttingposition. This angle may be such that the cutting tip bends to conformto the area between Schwalbe's line and the scleral spur (SS), an areathat encompasses SC. SC is narrow near the cornea and wider near the SSand thus an angled tip is best to present the tissue 20 to the two edgesof the TM. The ramp 13 of the cutting tip may be angled so that thetissue 20 is constantly elevated towards the blade as the tip isadvanced in circumferential pattern. Between the cutting tip and thefirst and second lateral blades 10, 11, the ramp 13 is shaped to avoidcutting tissue, such that the TM 20 that is elevated away from the outerwall of the Schlemm's canal 22 remains intact as it advances along theramp 13. For example, the ramp 13 can include convex or beveled edgesthat are not sharp enough to cut the TM 20. Endoscopic visualization mayalso be used to guide the cutting. In some embodiments, the device ofthe present disclosure may be placed at the end of an endoscope,precluding the need for a gonio lens during treatment. In someembodiments, the device of the present disclosure may be place at theend of an endoscope and the TM may be engaged under direct visualizationof the endoscope camera.

In some embodiments, a method for cutting a strip 20 a of tissue 20(e.g., TM) of width W from a tissue mass comprises the steps of: a)providing a device which comprises; i) a handle attached to a beveledplatform, ii) an anterior insertion blade tip of the beveled platformexpanding backwards to a posterior end of the beveled platform that isdevoid of cutting features, iii) a first side of the beveled platformupon which is affixed a first lateral blade, iv) a second side of thebeveled platform upon which is affixed a second lateral blade; v) atleast first and second lateral cutting edges formed by blades in agenerally perpendicular and posterior position to said opposite edges ofsaid anterior insertion blade tip of the beveled platform, said firstand second cutting edges being separated by a gap 14 of distance D thatis approximately equal to the width W of the strip 20 a of tissue 20 tobe cut (this is shown in FIG. 10, FIG. 13, and FIG. 15); b) advancingthe anterior insertion blade tip of the beveled platform through tissue20 such that the first and second cutting edges are positioned adjacentto tissue 20 to be cut; c) advancing the distal end such that thecutting edges cut a strip 20 a of tissue 20 of approximate width W andthe cut strip 20 a of tissue 20 remains substantially intact. In someembodiments, the mass of tissue 20 is in vivo. In some embodiments, themass of tissue 20 is in vitro. In some embodiments, said device isintegrated into an endoscope. In some embodiments, said cutting is underdirect visualization. In some embodiments, the mass of tissue 20 islocated within the body of a human or animal subject. In someembodiments, the strip 20 a of tissue 20 is removed for a diagnostic ortherapeutic purpose. In some embodiments, the subject suffers fromglaucoma and wherein the method is carried out to remove a strip 20 a oftrabecular meshwork from an eye of the subject to facilitate drainage ofaqueous humor from the eye thereby lowering intraocular pressure. Insome embodiments, said eye has a dilated pupil. In some embodiments,step b comprises inserting the device into the anterior chamber of theeye; positioning the anterior insertion blade tip of the beveledplatform adjacent to or within the trabecular meshwork of the eye; andadvancing the cutting tube such that the cutting edges cut a strip 20 aof approximate width W from the trabecular meshwork. In someembodiments, the device provided in step a of the method furthercomprises an anterior insertion blade tip of the beveled platform andwherein the anterior insertion blade tip of the beveled platform isadvanced through the trabecular meshwork and into Schlemm's canal and,thereafter, the anterior insertion blade tip of the beveled platform isadvanced through Schlemm's canal as the cutting tube is advanced to cutthe strip 20 a of tissue 20. In some embodiments, the device provided instep a further comprises apparatus for severing the strip 20 a of tissue20 after the strip 20 a of tissue 20 has reached a desired length andwherein the method further comprises the step of severing the strip 20 aof tissue after the strip 20 a of tissue 20 has reached a desiredlength. In some embodiments, the method is carried out to form anincision in skin, mucous membrane, an organ, a tumor or other anatomicalstructure. In some embodiments, the method is carried out to removetissue 20 from the vascular system. In some embodiments, the method iscarried out to remove tissue 20 from the lymphatic system. In someembodiments, the method further comprises the step of: c) removing thestrip 20 a of tissue 20.

It is not intended that embodiments of the present disclosure be limitedto any particular endoscope; it is believed that the device may beoptimally designed for an ophthalmic endoscopy system endoscope. Onesuch system is commercially called “Endo Optiks.”

The device could have a distal port that allows for injection of fluidto deliver local balanced salt solution, medication, viscoelastics ortherapeutic agents or to wash away reflux of blood that occurs duringthis type of procedure. The ultimate goal of this procedure may be toremove entire segments of TM without leaving significant leaflets oftissue behind (something that occurs with other devices that cut TMwithout conforming to the space of interest). The procedure might becombined with cataract extraction and can be performed before or afterthe cataract extraction and while the pupil is dilated. The proceduremight be coupled with other intraocular surgery such as iris orvitreous/retina based procedures.

Conditions that might benefit from use of this device include:

1. Primary open angle glaucoma

2. Normal or Low tension glaucoma

3. Pseudoexfoliation glaucoma

4. Pigment dispersion glaucoma

5. Angle closure glaucoma (acute, subacute, chronic)

6. Neo vascular or inflammatory glaucoma

7. Ocular hypertension

8. Other types of glaucoma that are related to high intraocular pressure

The device could be used for research purposes to harvest TM or othersmall sheath of tissue for lab based studies or to harvest cells for invitro culture needs. The device can be used to cut Anterior Synechiae orother cellular or fibrovascular membranes over the drainage angle suchas those seen with ICE syndrome or neovascular glaucoma.

It is not intended that embodiments of the present disclosure be limitedto any particular method, medical target, or device confirmation;however, it is believed that the device may be optimally designed toremove trabecular meshwork of the eye, unroofing small vessels (such asveins, arteries, lymphatic vessels, or other vessel with a lumen), andfor creating a hole or opening in the tympanic membrane of the ear. Itis not intended that embodiments of the present disclosure be limited toany particular mechanism; however, it is believed that creating anopening in the tympanic membrane of the ear may help aid in treating eardisease.

Examples

Procedures using traditional incisional goniotomy have certaindisadvantages. FIG. 20 shows an incision in trabecular meshworkextending into sclera with large segments of trabecular meshwork stillpresent. For this procedure (considered the gold standard surgery for“cutting” through the trabecular meshwork and traditionally called“goniotomy”) an MVR blade was used to create a single incision in thetrabecular meshwork to create an opening into Schlemm's canal. In thisphoto, there is a histological sample from a procedure in which anincision exists through Trabecular meshwork and extends into sclera.There are large leaflets of trabecular meshwork remaining on either sideof the incision. These leaflets scar down and close the opening that wascreated into Schlemm's canal. This preludes any long-term benefit inintraocular pressure lowering which is the goal of the surgery.

Procedures using a Trabectome® device also have certain disadvantages.For such a procedure (designed to replace goniotomy and to improve uponthat procedure by removing sections of trabecular meshwork) aTrabectome® device was used to engage the trabecular meshwork andcautery was applied to the trabecular meshwork, as shown in FIG. 21. Thecircle shows an area where a small segment of trabecular meshwork wasremoved; however, there are large leaflets of trabecular meshworkremaining and charred tissue on either side of the treatment area. FIG.21 shows post Trabectome® treatment showing trabecular meshwork remnantsand charring of tissue. Tissue debris is occluding a collector channelthis device “burns” tissue and the burning of tissue createsinflammation that leads to more scar formation that leads to failure ofthe surgically induced opening into Schlemm's canal. In addition, due tocautery, many bubbles are formed during the procedure that makesvisualization difficult during the actual procedure. These issues do notoccur with embodiments of the present disclosure, which is a majoradvantage.

FIG. 22 shows tissue after treatment with a device according toembodiments of the present disclosure. The data shows complete removalof trabecular meshwork with no remaining leaflets without any evidenceof tissue burning. The inset photo in FIG. 22 shows a close up of thecircled area. A representative photo of a device is in the inset on theleft of FIG. 22.

There is a second angle between the handle 1 and the ramp 13 that is notillustrated in FIG. 23. The ramp 13 does not only form an angle with thehandle 1 as shown in the picture to the right in FIG. 23. It also formsan angle in the z axis. (The pivot is at the “#”) away from the page asviewed. In some embodiments, the angle between the handle 1 and the ramp13 ranges between approximately 90 and 120 degrees. It is believed thatthe ramp 13 pierces the tissue wherein the tissue then slides up theramp 13 from A to B. The blades (*) then cut the tissue as the device isadvanced.

There exists a disadvantage of a conventional blade where the foot plateis sitting in Schlemm's canal. Because there is no ramp 13 and no secondangle between the tip and the handle, a second angle would have a pivotat the “*” which would create a pivot of the device inferiorly at theramp 13.

Referring now to FIGS. 24-26, a device 12 can be features similar tothose of the device 12 illustrated in other figures. As shown in FIG.24, a platform 5 of the device 12 can include a tip 6 at a distal sideof the platform 5 and a top surface (e.g., ramp) 13 extending from thedistal side of the platform 5 to a proximal side of the platform 5,opposite the distal side of the platform 5. For example, the top surface13 can extend from the tip 6 to one or more lateral elements 10, 11.

As further shown in FIG. 24, the platform 5 can include a bottom surface15 extending from the tip 6 at the distal side of the platform 5 to arear portion 7 of the platform 5, opposite the tip 6. The bottom surface15 of the device 12 can be positioned opposite the top surface 13. Thebottom surface 15 can be configured to abut the outer wall of theSchlemm's canal during a procedure (see FIGS. 19A-19C). At least aportion of the bottom surface 15 can be flat and/or planar. The rearportion 7 can define a curved or round surface that transitions from thebottom surface 15 to a portion of the shaft 4.

As shown in FIGS. 25 and 26, opposing sides 8, 9 of the platform 5 canextend downwardly from the top surface 13. The opposing sides 8, 9 canbe planar and/or parallel to each other. The top surface 13 cantransition to the opposing sides 8, 9 with a transition feature. While around bevel is shown in FIGS. 24-26, the transition feature can have oneor more other shapes, including curved, round, chamfer, fillet, etc.

A transition feature can be provided between the bottom surface 15 andthe opposing sides 8, 9. For example, the bottom surface 15 cantransition to the opposing sides 8, 9 with transition sections 28, 29,respectively. While chamfers are shown for transition sections 28, 29 inFIGS. 24-26, the transition feature can have one or more other shapes,including curved, round, beveled, fillet, etc. Along the transitionfeatures, the width of the device 12 can transition from a first width,between the opposing sides 8, 9, to a second width, less than the firstwidth, across the bottom surface 15. The transition from the first widthto the second width can be gradual, linear, stepwise, or another type oftransition.

Referring now to FIGS. 26-28, the bottom surface 15 of the device 12 caninclude surface features that enhance interactions with the outer wallof the Schlemm's canal during a procedure. For example, the bottomsurface 15 can be planar, convex, concave, or combinations thereof. Byfurther example, as shown in FIGS. 27 and 28, the bottom surface 15 caninclude a recessed portion 40 between at least two protrusions. Therecessed portion 40 can be defined by a gap, space, or void. A firstprotrusion 38 can be positioned below the first side 8 and/or the firsttransition section 28 of the platform 5. The first protrusion 38 can beformed, at least in part, by at least a portion of the first transitionsection 28. A second protrusion 39 can be positioned below the secondside 9 and/or the second transition section 29 of the platform 5. Thesecond protrusion 39 can be formed, at least in part, by at least aportion of the second transition section 29. Each of the protrusions 38,39 can extend from the rear portion 7 of the platform 5 toward the tip6. The protrusions 38, 39 can be separated by a recessed portion 40extending there between. As shown in FIGS. 26 and 27, a transitionbetween the protrusions 38, 39 and the recessed portion 40 can bestepwise, forming one or more edges. Additionally or alternatively, atransition between the protrusions 38, 39 and the recessed portion 40can be gradual, curved, round, beveled, chamfered, linear, or anothertype of transition. For example, the recessed portion 40 can include aconcave feature. The recessed portion 40 can extend to and intersect therear portion 7 of the platform 5.

Adjacent to the tip 6, the bottom surface 15 can provide a continuous(e.g., planar) portion 16 that is not interrupted by the recessedportion 40. The tip 6 can be separated from the recessed portion 40 bythe continuous portion 16. Accordingly, the bottom surface 15 caninclude a planar distal portion and a non-planar proximal portion alongthe length thereof. The tip 6 and the region (e.g., continuous portion16) immediately proximal to the tip 6 can be continuous, such that therecessed portion 40 does not intersect the tip 6. The recessed portion40 can extend distally from the rear portion 7, for example, not fartherthan the opposing sides 8, 9 and/or the transition sections 28, 29. Asshown in FIG. 28, the recessed portion 40 can terminate on a distal endthereof with a transition feature that is, for example, gradual, curved,round, beveled, chamfered, linear, stepwise, or another type oftransition.

The planar distal portion can provide an even surface to facilitateentry into tissue with the tip 6. The nonplanar proximal portion (e.g.,the protrusions 38, 39 and the recessed portion 40) can interact withthe Schlemm's canal during a procedure. As the platform 5 is moved, atleast some of the tissue can be received within the recessed portion 40between the protrusions 38, 39. The protrusions 38, 39 provide a smallersurface area for exposure to the tissue (e.g., Schlemm's canal).Accordingly, the nonplanar proximal portion of the bottom surface 15provides greater maneuverability of the platform 5 as it moves along thetissue.

FIG. 29 shows a cross section of the eye where one embodiment of handle1 is in the eye and going across to the opposite side Schlemm's canaloutlined by a circle. The angle between the handle 1 and the ramp 13will allow the blade to enter Schlemm's canal and cut tissue. In thisfigure, that first angle would make the ramp 13 come out towards theviewer. However, a second angle would also need to exist that followsthe black lines to allow the device to also fit in the angles space ofSchlemm's canal.

Approval for a preclinical study was obtained from the Colorado MultipleInstitutional Review Board for the use of human material prior toinitiation of the study and the tenets of the Declaration of Helsinkiwere followed. Informed consent was obtained from donors or relativesfor use in research by the eye bank from which human globes wereobtained.

For histologic analyses, 6 corneal rim specimens were obtained from theRocky Mountain Lions Eye Bank (Aurora, Colo., USA) and the San Diego EyeBank (San Diego, Calif., USA). Tissue samples were removed from thestorage medium and mounted on a platform with the TM side facing up andsecured in place using tissue pins. A total of 2 samples were used foreach of the 3 treatment methods studied. An MVR blade was used to createa single incision in the central TM under microscopic visualizationalong the length of 2 corneal rims. For the Trabectome® device, the footplate of the device tip was inserted into the Schlemm's canal undermicroscopic visualization. Once in place, the foot pedal was used toapply continuous ablation while advancing the tip slowly across theextent of the TM sample. A standard power setting of 0.8 W was usedduring treatment. The dual-blade device was used to incise the TM of 2samples. The blade tip was used to incise TM in a manner similar to thatused for goniotomy and the blade was then advanced in a clockwisefashion along the extent of the TM. At the distal end, the blade tip wastilted upwards to incise a complete ribbon of TM and the process wasrepeated in a counterclockwise fashion to incise the remaining TMtissue.

All tissue samples were then immediately preserved in 4%paraformaldehyde/phosphate-buffered saline overnight at 4° C. and thenradially cut into quadrants. Rim sections were processed for histologyand embedded into paraffin so that the cut edge of the tissue was facingthe front of the block. Tissue sections (6 mm thick) were cut andstained with Mayer's hematoxylin-eosin Y (Richard-Allan Scientific,Kalamazoo, Mich., USA). Bright-field imaging was performed using a NikonEclipse 80i microscope (Nikon, Melville, N.Y., USA) equipped with aNikon D5-Fil color camera and a Nikon CFI 103/Plan Fluor objective lens.

Human eye perfusion Studies: A total of 12 human globes frompseudophakic donors with no history of glaucoma were obtained fromvarious eye banks around the country for perfusion studies on eachdevice. The perfusion system used a standard programmable syringe pump(Pump 11 Plus; Harvard Apparatus, Holliston, Mass., USA). Pressure wasmonitored via an in-line real-time pressure transducer (Research GradePressure Transducer; Harvard Apparatus) connected to a single-channelchart recorder (Pharmacia REC-481; Pharmacia/Pfizer New York, N.Y.,USA). Polyethylene tubing with a 1.14 mm inner diameter (PE-160; WarnerInstruments, Hamden, Conn., USA) was used for all connections.

In each case, the human globe was first prepared by injecting Dulbecco'smodified Eagle medium (DMEM; Invitrogen/Life Technologies, Carlsbad,Calif., USA) through the optic nerve with a 26-gauge needle until theglobe had returned to a spherical shape. The perfusion line (terminatingin another 26-gauge needle) was inserted diagonally through the anteriorchamber of the eye, passing through the cornea and pupil and ending withthe tip beneath the iris. The globe was surrounded by damp gauze and theperfusion pump (filled with DMEM) was set to an initial inflow rate of 7mL/min. IOP was allowed to increase until it reached 30 mm Hg. Theinfusion rate was then reduced to 2-5 mL/min to maintain a steady-stateIOP for at least 60 minutes prior to TM incision. A preoperative IOP wasmeasured immediately prior to incision in each case. A 1.7 mm stainlesssteel keratome blade (BD) was used create a tri-beveled clear cornealincision near the limbus, and the anterior chamber was filled withenough viscoelastic (HealonGV; Abbott Medical Optics, Abbott Park, Ill.,USA) to maintain the anterior chamber and provide adequate visualizationduring the procedure in each case. Each technique was performed undergonioscopic view using a standard direct gonioscope with microscopeassistance. The surgical procedure used for each device is describedabove. In each case, approximately 100-180 degrees of TM was treated.For each device, treatment was started 180 degrees away from the cornealwound and extended along the angle in a clockwise direction. The devicewas then extended in a counterclockwise direction from the same startingpoint. Every effort was made to treat the maximum amount of degreespossible with each device. In the case of the dual-blade device andTrabectome®, the instrument was rotated 180 degrees after the initialpass to direct the device tip in the direction of treatment. TOP wasallowed to reach a steady state before measuring the postprocedure TOP.Each of the 3 studied surgical techniques was performed on a total of 4eyes.

The mean and standard deviation of preprocedure and postprocedure TOPwas calculated for each device as well as percent change in TOP. Studentpaired t tests were used to compare preprocedure and postprocedure TOPfor each device. A calculated P value<0.05 was considered to bestatistically significant.

Two corneal rim sections were analyzed for each device. Six-micron-thickhistologic sections were taken from various clock hours treated witheach device and stained with Mayer's hematoxylin-eosin Y (Richard-AllanScientific). Findings were consistent across all sections from eachdevice tested. Cuts with the MVR blade exhibited complete incisionthrough the entire thickness of TM tissue. However, there was minimalremoval of TM with large leaflets of tissue remaining over the Schlemm'scanal. The incision extended deeply through the Schlemm's canal withobvious injury to the adjacent deep sclera in the majority of sections(FIG. 1). The Trabectome® also achieved an opening through the entiretyof TM tissue into the Schlemm's canal. Although the device also removeda large portion of the central TM, significant leaflets of residualtissue still remained. The residual TM demonstrated extensive charringfrom thermal injury. Tissue debris was also noted to be occluding distalcollector channels (FIG. 2). Tissue incised with the dual-blade devicedemonstrated a more complete removal of TM without collateral damage(FIG. 3).

Data from human eye perfusion studies are included in Table 1. Theextent of TM treatment varied between devices and between eyes from 100to 180 degrees. All 3 treatment modalities achieved a significantreduction in measured TOP 30 minutes after treatment. Treatment with thedual-blade device and Trabectome® resulted in a mean TOP reduction of40% each, whereas the MVR blade achieved a 31% reduction. Although thepercentage of TOP decrease was greater for Trabectome® and thedual-blade device, there was no statistically significant difference inthe TOP lowering between devices (dual-blade/MVR P=0.13;dual-blade/Trabectome®P=0.96; Trabectome®/MVR P=0.12). There was nocorrelation between the number of degrees of TM treated and thepercentage IOP change for any device (r2=0.077-0.271).

TABLE 1 Human Eye Perfusion Studies After Treatment of TrabecularMeshwork by Various Devices Degrees Pre- Post- Absolute Percent of Angleprocedure procedure IOP IOP Eye Treated IOP IOP Change Change P ValueDual-blade 1 140 17 10 −7 −41 0.00063 device 2 180 19 11 −8 −42 3 130 15 9 −6 −40 4 180 22 14 −8 −36 Mean 157.5 ± 26.3 18.3 ± 3.0 11.0 ± 2.2−7.3 −40 MVR blade 1 180 20 14 −6 −30 0.00018 2 180 20 15 −5 −25 3 15018 12 −6 −33 4 170 16 10 −6 −38 Mean 170.0 ± 14.1 18.5 ± 1.9 12.8 ± 2.2−5.8 −31 Trabectome ® 1 120 18 12 −6 −33 0.00324 2 130 21 12 −9 −43 3100 17 11 −6 −35 4 120 19 10 −9 −47 Mean 117.5 ± 12.6 18.8 ± 1.7 11.3 ±1.0 −7.5 −40 IOP = intraocular pressure; MVR = mirovitreoretinal.

Histologic analysis of human cadaver eye tissue treated with thedual-blade device achieved more complete removal of TM tissue whileavoiding any discernible damage to surrounding tissue. Treatment withother methods of TM removal such as MVR blade goniotomy and ab internotrabeculectomy with the Trabectome® device failed to attain equivalenthistologic results to the dual-blade device. While histology data wereobtained from ex vivo-treated corneal rims, similar findings were notedwhen treatment was performed using the ab interno approach on perfusedeyes. The near-absence of TM leaflets with the dual-blade device may bebeneficial in reducing the chances of future physical obstruction, andthe lack of tissue damage may also reduce the inflammatory response orsubsequent fibrosis at the surgical site.

In addition to potentially favorable histologic outcomes, the dual-bladedevice resulted in significant TOP lowering in a human eye perfusionmodel. Although all 3 devices yielded similar immediate reduction in TOPafter use in a perfusion model, it is unclear how a more completeremoval of TM tissue and decreased collateral damage with the dual-bladedevice of the present disclosure will translate into long term surgicaloutcomes when used to treat glaucoma. No correlation was found betweendegrees of TM treated and TOP reduction. It is plausible that TOPreduction may depend more on the number of downstream collector channelsexposed rather than the absolute amount of TM removal alone.

In an effort to provide a low-cost MIGS device that can be widely usedby ophthalmic surgeons, one embodiment of the present disclosurecontemplates a medical-grade stainless steel dual-blade device that cansuccessfully remove TM with no discernible collateral damage wasdesigned. In some embodiments, the device comprises a unique dual-edgeblade design using precise geometries to allow for more complete removalof TM tissue (FIG. 4). It is believed that the procedure is performedfrom an ab interno approach and is viscoelastic to maintain the anteriorchamber. For example, the size and tip of the blade can allow for asmooth entry into the Schlemm's canal, similar to techniques used fortraditional goniotomy procedures. Once in place, the tip is advancedthrough the Schlemm's canal and the TM is elevated along a designed rampthat guides tissue toward a set of blades positioned specifically toincise and remove TM. In contrast to the Trabectome® footplate, which isjuxtaposed between the outer wall of the Schlemm's canal and the innerwall of the Schlemm's canal to provide protection during cautery, thedual-blade device transects TM and elevates TM away from the outer wallof the Schlemm's canal. It is believed that by elevating the TM alongthe ramp of the device as it moves forward leads to maximal tissueremoval when incised by the superiorly placed and strategically angleddual blades. It is further believed that the angle between the distalcutting edge and the handle is engineered to allow maximal angletreatment through 1 incision while avoiding trauma to the cornea aboveor the scleral spur below. The excised TM may then be removed from theeye with forceps or aspirated during the irrigation/aspiration phase ifcombined with cataract extraction. In addition, the device according toembodiments of the present disclosure can easily pass through clearcorneal incisions as small as 1.2 mm, thus obviating the need foradditional incisions when coupled with phacoemulsification.

Another device known in the art that has been used for ab intemotrabeculectomy is known as the “gonioscraper,” as described by Jacobiand associates. This device consisted of a handle and curette tip andwas used to remove TM by scraping the curette within the Schlemm'scanal. The curette tip is in line with the handle and does not conformto the geometry of the drainage angle and adjacent structures. Afterpromising preclinical experiments, a nonrandomized clinical trial of 25eyes was completed. Preoperative IOP was 34.7±7.1 mm Hg on 2.2±0.56medications and mean follow-up time was 32 months. Based on the successcriteria of postoperative IOP of 19 mm Hg or less with 1pressure-reducing agent, 15 eyes (60%) were successful. Nonetheless,complications developed in some patients including localized Descemetmembrane detachments and/or anterior chamber bleeding. Histologicanalysis of banked human eyes treated with the curettage showedsuccessful removal of TM tissue, but with damage to the septa andendothelium of the external and posterior wall of the Schlemm's canal.In the data presented herein, similar damage to adjacent sclera was alsoobserved when using the MVR blade, but was notably absent with use ofone embodiment of a dual-blade device as contemplated by the presentdisclosure. In addition, the present disclosure contemplates a bladedevice geometry designed to minimize any impact to adjacent tissues suchas Descemet membrane by leveraging specific angles between the handleand the distal blade as well as use of specific angles between thecutting blade and the adjacent cutting tip.

There have been reports of both success and failure with the Trabectome®device over the past few years. In a recent retrospective study ofTrabectome® versus ab externo trabeculectomy, poor success rates werefound in eyes treated with Trabectome® at 2 years. Of the 115 eyestreated with Trabectome®, only 22.4% achieved success with failuredefined as IOP>21 mm Hg or <20% reduction in IOP. It is conceivablethat, after initial opening of the canal with TM removal, the residualleaflets occlude the Schlemm's canal and/or the more distal collectorchannels, leading to failure of the intervention. This mechanism offailure after Trabectome® treatment would be overcome by the dual-bladedevice, as a more complete removal of TM tissue is produced withoutresidual leaflets.

The foregoing description is provided to enable a person skilled in theart to practice the various configurations described herein. While thesubject technology has been particularly described with reference to thevarious figures and configurations, it should be understood that theseare for illustration purposes only and should not be taken as limitingthe scope of the subject technology.

There may be many other ways to implement the subject technology.Various functions and elements described herein may be partitioneddifferently from those shown without departing from the scope of thesubject technology. Various modifications to these configurations willbe readily apparent to those skilled in the art, and generic principlesdefined herein may be applied to other configurations. Thus, manychanges and modifications may be made to the subject technology, by onehaving ordinary skill in the art, without departing from the scope ofthe subject technology.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Some of the stepsmay be performed simultaneously. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

A phrase such as “an aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples of the disclosure. A phrasesuch as “an aspect” may refer to one or more aspects and vice versa. Aphrase such as “an embodiment” does not imply that such embodiment isessential to the subject technology or that such embodiment applies toall configurations of the subject technology. A disclosure relating toan embodiment may apply to all embodiments, or one or more embodiments.An embodiment may provide one or more examples of the disclosure. Aphrase such “an embodiment” may refer to one or more embodiments andvice versa. A phrase such as “a configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples of the disclosure. A phrase such as “a configuration” may referto one or more configurations and vice versa.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” does not require selection ofat least one of each item listed; rather, the phrase allows a meaningthat includes at least one of any one of the items, and/or at least oneof any combination of the items, and/or at least one of each of theitems. By way of example, the phrases “at least one of A, B, and C” or“at least one of A, B, or C” each refer to only A, only B, or only C;any combination of A, B, and C; and/or at least one of each of A, B, andC.

Terms such as “top,” “bottom,” “front,” “rear” and the like as used inthis disclosure should be understood as referring to an arbitrary frameof reference, rather than to the ordinary gravitational frame ofreference. Thus, a top surface, a bottom surface, a front surface, and arear surface may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference.

Furthermore, to the extent that the term “include,” “have,” or the likeis used in the description or the claims, such term is intended to beinclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.”Pronouns in the masculine (e.g., his) include the feminine and neutergender (e.g., her and its) and vice versa. The term “some” refers to oneor more. Underlined and/or italicized headings and subheadings are usedfor convenience only, do not limit the subject technology, and are notreferred to in connection with the interpretation of the description ofthe subject technology. All structural and functional equivalents to theelements of the various configurations described throughout thisdisclosure that are known or later come to be known to those of ordinaryskill in the art are expressly incorporated herein by reference andintended to be encompassed by the subject technology. Moreover, nothingdisclosed herein is intended to be dedicated to the public regardless ofwhether such disclosure is explicitly recited in the above description.

While certain aspects and embodiments of the subject technology havebeen described, these have been presented by way of example only, andare not intended to limit the scope of the subject technology. Indeed,the novel methods and systems described herein may be embodied in avariety of other forms without departing from the spirit thereof. Theaccompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thesubject technology.

What is claimed is:
 1. A device for incising a trabecular meshwork, thedevice comprising: a platform for elevating a portion of the trabecularmeshwork away from an outer wall of a Schlemm's canal, the platformcomprising a tip at a distal side of the platform and a top surfaceextending from the distal side to a proximal side of the platform,opposite the distal side of the platform; first and second sidesextending from the top surface, wherein the first and second sides areparallel to each other; first and second lateral elements for creatingfirst and second incisions through the trabecular meshwork, the firstand second lateral elements extending from the proximal side of theplatform; and a bottom surface, opposite the top surface, wherein thebottom surface comprises first and second protrusions separated by a gapand a planar portion adjacent the tip, wherein the tip is separated fromthe gap by the planar portion.
 2. The device of claim 1, wherein thefirst protrusion is parallel to the first side and the second protrusionis parallel to the second side.
 3. The device of claim 1, wherein thebottom surface has a maximum width that is less than a maximum width ofthe platform.
 4. The device of claim 1, wherein the platform forms afirst bevel connecting the top surface to the first side and a secondbevel connecting the top surface to the second side.
 5. The device ofclaim 1, wherein the gap extends from the proximal side of the platformto the planar portion of the bottom surface.
 6. The device of claim 1,wherein the gap comprises a rounded distal end transitioning into theplanar portion of the bottom surface.
 7. The device of claim 1, whereinthe bottom surface connects to a rear surface of the device, oppositethe tip, with a rounded surface.
 8. The device of claim 1, wherein thefirst and second protrusions connect to a rear surface of the device,opposite the tip, with rounded surfaces.
 9. The device of claim 8,wherein the gap extends to the rear surface.
 10. The device of claim 1,wherein a transition between the first and second protrusions and thegap is stepwise and forms one or more edges.
 11. The device of claim 1,wherein a transition between the first and second protrusions and thegap is curved and forms a concave feature.
 12. A device for incising atrabecular meshwork, the device comprising: a platform for elevating aportion of the trabecular meshwork away from an outer wall of aSchlemm's canal, the platform comprising a tip at a first end of theplatform and a top surface extending from the first end to a second endof the platform; first and second lateral elements for creating firstand second incisions through the trabecular meshwork, the first andsecond lateral elements extending from the second end of the platform;and a bottom surface, opposite the top surface, wherein the bottomsurface comprises first and second protrusions separated by a gap and aplanar portion adjacent the tip, wherein the tip is separated from thegap by the planar portion.
 13. The device of claim 12, furthercomprising first and second sides extending from the top surface,wherein the first protrusion is parallel to the first side and thesecond protrusion is parallel to the second side.
 14. The device ofclaim 12, wherein the bottom surface has a maximum width that is lessthan a maximum width of the platform.
 15. The device of claim 12,wherein the gap extends from the second end of the platform to theplanar portion of the bottom surface.
 16. The device of claim 12,wherein the gap comprises a rounded end transitioning into the planarportion of the bottom surface.
 17. The device of claim 12, wherein thefirst and second protrusions connect to an outer surface of the secondend with rounded surfaces, and wherein the gap extends to the outersurface.
 18. The device of claim 12, wherein a transition between thefirst and second protrusions and the gap is stepwise and forms one ormore edges.
 19. The device of claim 12, wherein a transition between thefirst and second protrusions and the gap is curved and forms a concavefeature.
 20. A method of incising a trabecular meshwork, the methodcomprising: inserting the tip of the device of claim 12 into a Schlemm'scanal of an eye; placing the bottom surface of the device into contactwith an outer wall of the Schlemm's canal; moving the device along aportion of the Schlemm's canal; creating first and second incisionsthrough the trabecular meshwork with the first and second lateralelements; and receiving a portion of Schlemm's canal tissue into the gapbetween the first and second protrusions.